Our long-range objective is to understand the cellular mechanisms controlling membrane processes in brain. The objective of the present study is to identify the processes controlling the biosynthesis of membrane-bound carbonic anhydrase in the CNS and to elucidate the mechanisms for the incorporation of the enzyme into the myelin sheath. Using a tissue slice technique, we will determine the rate of biosynthesis of carbonic anhydrase and its incorporation into myelin and plasma membrane as compared with the soluble enzyme. Several pulse chase protocol will be used to determine possible precursor-product relationships between the soluble and membrane-bound forms of carbonic anhydrase and among the different membrane fractions. Factors required for the incorporation of the enzyme into membranes will be identified in reconstituted systems using subcellular fractions derived from both tissues which synthesize membrane-bound carbonic anhydrase and those which do not. In this way we will study either the conversion of the soluble to the membrane bound enzyme or, alternatively, the direct synthesis and membrane insertion of carbonic anhydrase by a cell-free protein synthesis. These experiments will be complemented with examination of neuroendocrine control by examining the effects of adenalectomy and steroid replacement therapy on membrane bound carbonic anhydrase biosynthesis. These studies are directed towards an understanding of the normal processes which give rise to membrane bound carbonic anhydrase in brain and will allow for a more critical approach to the study of the physiologic role of the enzyme in controlling ionic disequilibria, edema and disruption of myelin by vacuolization.